One-Pot Spaghetti Puttanesca is full of big, bold flavors from the anchovies, Kalamata olives, and capers – the trifecta for a winning puttanesca. Heat oil in a large skillet (with high sides) over medium heat. Add garlic and cook, stirring, for 2 minutes. Stir in tomato paste and continue to cook for 1 more minute.
Saute mixture until anchovies melt into oil and completely dissolve and garlic is tender, about 3 minutes: your kitchen never smelled so good! Add olives, capers, tomatoes, black pepper, and parsley. Bring sauce to a bubble, reduce heat, and simmer 8 to 10 minutes. Toss sauce with cooked pasta.
Add the olives, capers, tomatoes/passata, and pasta cooking water. Bring to a boil, reduce the heat to low and cook for 15 minutes (stirring from time to time) until the sauce has thickened. After this time, season the sauce lightly with salt and pepper. Be careful with adding salt (!), because anchovies, olives, and capers are already salty.
Add the anchovy filets 6 and desalinated capers 7. Brown over medium heat for 5 minutes stirring frequently, so the anchovies melt and release their aroma. After this time, pour in the lightly crushed peeled tomatoes 8, stir with a spoon, and cook for another 10 minutes over medium heat.